In recent years, a mobile information terminal has increased in speed of a central processing unit (CPU) and in communication speed, and this causes an increase in amount of information to be handled by the mobile information terminal. Furthermore, due to reduction in cost for various devices (e.g., a memory) necessary for processing information in such an amount, a display typified by a liquid crystal display and an organic electro luminescence (EL) display tend to be increased in size. This allows many pieces of information to be simultaneously displayed on a screen of the display.
A conventional mobile phone has many hardware keys such as a dial key. However, a mobile phone has come to have a large-sized display, so as to be able to display a user interface (UI) component in a large size allowing a user to conduct an operation by directly touching the UI component. In order to increase a size of a display without causing a problem in size of a terminal including the display, the mainstream of terminals is a terminal in which (i) a hardware key is eliminated as much as possible and (ii) a display (touch panel) to which an operation function is imparted is employed as a display. In recent years, therefore, an increasing number of applications are compliant with only a touch operation and are not compliant with a key input.
However, there are still users who prefer a small-sized terminal. Users (e.g., senior users) who feel it difficult to conduct a touch operation still have a high demand for using an application by conducting a conventional key input operation. Such users cannot use an application which is compliant with only a touch operation. Providers of applications have a problem that in order to address such a situation, burden of developing software for addressing an operation conducted with respect to a hardware key is increased.
In regard to a key input, for example, the Japanese Patent Application Publication, Tokukai, No. 2001-142595 (Patent Literature 1) discloses a key input device for “enabling an operation conducted via a mouse, a pointing device, and a touch panel by using only a keyboard”. Specifically, according to the key input device, “an input section 2 is constituted by a keyboard including a character key, a conversion key, and a selection key. In a case where the character key is operated so that a character string is inputted, and then a conversion key is operated, a CPU 1 stores the character string in an RAM 3. The CPU 1 then controls a display section 6 to display a plurality of candidates for conversion which candidates correspond to the character string thus inputted, from a conversion dictionary storing therein (i) a candidate for a converted character string into which the character string thus inputted has been converted and (ii) a plurality of candidates for conversion including a predetermined command candidate. In a case where a command candidate has been selected by an operation conducted with respect to the selection key, the CPU 1 carries out a command process based on the command candidate. If necessary, a document prepared by performing the command process is written into a storage medium 5 by a storage device 4, printed by a printing section 7, and then transmitted from a transmission control section 8.” (see “Abstract”).